The <attrdefault> Tag

Attributes are usually specified inside a content item's <content> or <contents> tags, or, for output files, inside
the <out> tag. However, this can be a chore if you have many
items to set attributes on, so, to make things easier, you can specify default
attributes using the <attrdefault> tag.

Specify this tag before the content items or output files in question, and
those items will all be tagged with the attributes you set.

Like the metadefault tag, this tag can be used either in a
scoped mode, or in a command mode.